Textile drafting apparatus



June 6, 1967 s. L. ABBOTT 3,323,180

TEXTILE DRAFTlNG APPARATUS FiledJan. 20, 1964 2 Sheets-$he-et 1 June 6, 1967 s. 1.. ABBOTT TEXTILE DRAFTlNG APPARATUS 2 Sheets-Sheet 2 Filed Jan. 20, I964 United States Patent 3,323,180 TEXTILE DRAFTING APPARATUS Samuel L. Abbott, Wilton, N.H., assignor to Abbott Machine Co., Inc., Wilton, N.H., a corporation of New Hampshire Filed Jan. 20, 1964, Ser. No. 338,908 Claims. (Cl. 19-288) This invention relates to textile drafting apparatus of the type in which a roving or sliver in the drafting zone is contained in a longitudinal passage defined by a group of members which are moved back and forth longitudinally of the roving or sliver in out-of-phase relation, faster backwardly than forwardly, so as to exert a net forward feeding action, apparatus of this type being disclosed in my United States Patent No. 2,626,431 and corresponding patents of other countries. An advantage of such apparatus is that the longitudinally movable members, sometimes referred to as fingers, can extend up close to the nip of the front rolls of the machine and there confine the roving. The fingers also frictionally urge forwardly the engaged fibers insofar as these have not been gripped by the fast-moving front rolls.

Principal objects of the invention are to provide a more definite forward pull on the main body of the roving in the drafting zone, and also to reduce the percentage variation in the force urging the roving forwardly. It is an object of the invention to accomplish these results without interference with the operation of the fingers in confining the roving as it approaches the nip of the front rolls.

In the drawings:

FIG. 1 is a side elevation, partly in vertical section, of a unit of drafting apparatus according to the present invention;

FIG. 2 is a view in the nature of a plan, taken on line 22 of FIG. 1;

FIG. 3 is a vertical section taken on the lines 33 of FIG. 2, omitting some parts;

FIG. 4 is a transverse section taken on the line 44 of FIG. 2;

FIG. 5 is a transverse section taken on the line 55 of FIG. 2; and

FIG. 6 is a diagram, taken from the same point of view as FIG. 2 showing only the two upper fingers of the apparatus. 4

Conventional upper and lower front rolls 10 and 11 nip the roving R at the front of the drafting zone. Any suitable feeding means in geared relation to the driven lower front roll, 11, grips the roving and determines the rate of its entry at the rear of the drafting zone. By way of example such feeding means at the rear of the drafting zone is shown as a rotary member 12 corresponding to the rotary member 12 of my United States patent application Serial No. 90,062, filed February 17, 1961, patented June 2, 1964, Patent No. 3,135,025, carrying a group of slides 21 slidable in slots therein and together forming a surface around which the roving is wrapped several times so that the frictional snubbing engagement of the tensioned roving causes it to be firmly gripped by this rotatable member 12.

It may be noted that the rotatable member 12 of the prior application has its axis parallel to the axes of the front rolls, but in the machine illustrated in this present application the rotatable member 12 for convenience has been turned 90 degrees from such position and projects normally upward and outward from what would usually be considered the roll stand.

The slides 21 are cam operated to reciprocate longitudinally in out-of-phase relation faster in the downward direction than in the upward direction so as to shift the roving upward, axially of the rotating member 12.

3,323,180 Patented June 6, 196'? A stationary guide wire 22 is provided to insure a definite spacing between the convolutions of the roving as these progress upwardly.

So far as the present invention is concerned, the member 12 could be replaced by conventional rear rolls or any other suitable feed means appropriate to define the rear end of the drafting zone.

The device shown in the drawings includes four reciprocating fingers 31, 32, 33 and 34, which form a longitudinal passage for the roving. Fingers 31 and 34 are of two-part construction comprising plate elements 31a, 34a respectively, and bar elements 31b, 34b respectively, as indicated in FIG. 4, the two parts of each being held together by screws 35, FIG. 2. The plate elements of these fingers 31, 34 overlie the fingers 32, 33. Accordingly fingers 31 i and 34 may be referred to as the upper fingers and fingers 32., 33 as the lower fingers.

The four fingers are slidingly confined between side guide elements 37 carried by a box-like casing 38 stationarily mounted in the machine. At their rear ends all four fingers are supported by and slide on a cross-web 38a of the casing 38. At their forward ends the lower fingers 32, 33 are supported by and slide on a plunger 39 which is received in the casing and urged upwardly by a spring 40. At their forward ends the upper fingers rest by dead weight upon the roving being drafted.

For reciprocating the fingers a shaft 42, which may if desired be common to a suitable number of units, carries four cams 43, one for each finger. Each cam operates a follower roll 44 carried by an arm 46 pivoted at 47. The upper end of each arm 46 has a portion of reduced thickness fitting into a slot 48 of the corresponding reciprocating finger, one such slot being shown in FIG. 3. The lower end of arm 46 works against a compression spring 50. The effect of this construction is that each finger is moved quickly to the rear when permitted by its cam 43. In FIG. 1 the cam 43 for operating slide finger 34 is shown. Each cam is a two-throw cam having slow rises and fast falls so that the forward movement of the finger is much slower than the rearward movement. Thus of 180 cam rotation, about 30 may correspond to the fast rearward movement and about to the slow forward movement.

The four cams are displaced angularly on the shaft so that the stokes of the four fingers are displaced at equal time intervals. Thus, successive 45 degrees of rotation of the cam shaft will mark the beginnings of cycles of respective ones of the four fingers. The order of movement of the fingers is for example 31, 33, 34 and 32, etc. Any other order may be used, but it is preferable to avoid an order which places the two lower fingers in consecutive relation.

The two upper fingers have their plate elements 31a and 34a cut away at 55, providing a space into which extends a continuously and positively driven roll 56 which there bears upon the roving which is supported by the two lower fingers. The surface of this roll preferably has a considerably higher frictional grip on the rov ing than do any of the smooth surfaced. fingers. Preferably, as shown, the roll 56 has its roving-engaging surface serrated, whereas the roving-engaging surfaces of the fingers are smooth.

The lower fingers 32, 33 are yieldingly urged upwardly, as mentioned above, and yieldingly urge the roving against the roll 56 with light pressure. Each lower finger 32, 33 is moreover longitudinally slotted as indicated at 59', FIG. 3, throughout most of its length, whereby its upper portion is thin and resilient at the point of nip with the roll 56.

At the rear of the roll 56 the side faces of the plate elements of the upper fingers define the sides of a generally U-shaped passage for guiding the roving, the bottom of which passage is formed by the lower two fingers. In the region of the roll 56 the upper fingers are cut away as previously indicated, and as shown in FIG. the upper adjacent edges of lower fingers 32, 33 are slightly beveled.

Beyond the roll 56, that is, in front of the roll, the bevel of the lower fingers continues and the upper fingers are shaped to approach each other and overlie the roving and nearly touch, these also being beveled as shown in FIG. 4 so as to form with the lower fingers a confining passage of approximately diamond-shaped section. In this region between the roll and the front of the fingers the roving passage is to some extent tapered to conform to the diminishing size of the roving as the latter is drafted. The upper fingers bear on the roving by dead weight.

The provision of the roll 56 permits the roving to have a higher tension at this point than if it were confined by reciprocating fingers alone. Thus the variable interfiber pull on the roving, caused by the drafting fibers, will cause less percent-age variation of the tension. In this way, evenness of drafting is promoted.

Without interfering with the confining action of the fingers near the nip of the front rolls, the present invention overcomes a limitation in the reciprocating finger type of drafting apparatus. As will be seen from my patent referred to above, an early conception of this type of apparatus contemplated six fingers. However, it is evident that four instead of six make a simpler construction. When care is taken to time such apparatus so that each finger reverses its rearward motion and starts forward before any other finger starts to move rearwardly there are times when all four fingers are moving forward. This represents the maximum of forward feeding action. On the other hand, a rearwardly moving finger will tend to nullify the action of a forwardly moving finger. If all four fingers present equal areas to the roving a rearwardly moving finger may be considered to offset the forward feeding action of one forwardly moving finger. Thus, the net forward feeding action, may be considered to vary from four to two, or from a maximum of 100% to 50%.

With stretchy roving, that is, roving such as will stretch, such variation in the forward feeding action has the effect of introducing irregularities in the drafting because of its tendency to vary the rate of delivery of the fibers to the front rolls.

A rearwardly moving finger will, of course, tend to reduce forward feeding action in the present device. However, at the line of nip between the continually driven roll 56 and the lower fingers 32, 33, each lower finger presents a lower coefficient of friction to the roving than does the roll 56, so that at this place, where the feeding action is at its maximum, rearward movement of a lower finger will cause considerably less than 50% reduction in net forward feeding action. At this point the roving will be somewhat flattened and thinned and that part thereof which lies on a momentarily rearwardly moving finger may be considered as preferentially following the forward feeding action of the roll rather than the rearwardly feeding tendency of the finger.

As previously mentioned, the order of movement of the fingers is preferably such as to avoid having the two lower fingers in consecutive order. Thus rearward movement of an upper finger is preferably interspersed between successive rearward movements of the lower fingers. This assures that at the nip of roll 56, where the upper fingers are cut away, the recurring rearwardly-feeding tendencies of the two lower fingers will be spaced apart, timewise, as much as possible, giving the maximum time for recovery of the roving from such tendency of a finger.

The fact that the roll 56' is serrated does not prevent the drafting of fibers which extend back from the grip of the front rolls past the roll 56, because of the light pressure with which the lower fingers press the roving against this roll.

Since the maximum forward feeding action occurs at the roll 56, the out-of-phase actuation of the fingers may be regarded primarily as a means for enabling the roving to pass through a closely confining passage without rupture by reason of excessive frictional rearward drag. The momentarily forwardly moving fingers, though moving slower than a rearwardly moving finger, will move faster than the main bulk of the roving.

I claim:

1. Textile drafting apparatus of the type comprising a group of members defining -a longitudinal passage containing a roving in a drafting zone, means for moving said members back and forth longitudinally of the roving in out-of-phase relation, faster backwardly than forwardly, the apparatus including a continually driven roll engaging the roving and pressing the roving against at least two of said members within the drafting zone, at least two of said members which overlie the roving in the front of the drafting zone being cut away farther back in the drafting zone to expose the roving to the action of the roll.

2. Textile drafting apparatus as claimed in claim 1 in which the roving-engaging surfaces of the members have a lower coefiicient of friction than the roving-engaging surface of the roll.

3. Textile drafting apparatus including a plurality of longitudinally movable members together defining a longitudinal passage for a roving in a drafting zone; two of said members which have portions overlying the roving, in the front of the drafting zone being cut away in a region farther back in said zone, a roll extending intov the cutaway region and mounted so as to engage and bear against the roving supported by two others of said members underlying the roving, and means for yieldingly urging said underlying members toward the roll.

4. Textile drafting apparatus as claimed in claim 3, in which said members underlying the roving have a longitudinal slot underlying the surface which underlies the roving thereby rendering their upper portions resilient where they support the roving engaged by the roll.

5. Tex-tile drafting apparatus as claimed in claim 3, in which the members which overlie the roving bear on the roving by dead weight.

References Cited UNITED STATES PATENTS 1,444,658 2/1923 Butler 19287 X 2,328,899 9/1943 Goodspeed 19286 2,932,858 4/1960 Kawabata 19-228 X 3,145,431 8/1964 Rulon-Miller et al. 19--288 X MERVIN STEIN, Primary Examiner.

DORSEY NEWTON, Examiner. 

1. TEXTILE DRAFTING APPARATUS OF THE TYPE COMPRISING A GROUP OF MEMBERS DEFINING A LONGITUDINAL PASSAGE CONTAINING A ROVING IN A DRAFTING ZONE, MEANS FOR MOVING SAID MEMBERS BACK AND FORTH LONGITUDINALLY OF THE ROVING IN OUT-OF-PHASE RELATION, FASTER BACKWARDLY THAN FORWARDLY, THE APPARATUS INCLUDING A CONTINUALLY DRIVEN ROLL ENGAGING THE ROVING AND PRESSING THE ROVING AGAINST AT LEAST TWO OF SAID MEMBERS WITHIN THE DRAFTING ZONE, AT LEAST TWO OF SAID MEMBERS WHICH OVERLIE THE ROVING IN THE FRONT OF THE DRAFTING ZONE BEING CUT AWAY FARTHER BACK IN THE DRAFTING ZONE TO EXPOSE THE ROVING TO THE ACTION OF THE ROLL. 